This invention relates to power assisted landscaping machines, and in particular to such devices for lawn edging and trenching.
Quality landscaping today often involves extensive detailed demarcations between plant and floral bed areas and lawns. In addition, lawns frequently require trenches to be dug for such tasks as cable installation, underground irrigation systems, installing drainage piping, and so on. Landscaped areas associated with parks, government buildings, hospitals, and other extensive lawns obviously require mechanized equipment for economical maintenance of these grassy areas. And the increased sophistication of home owner's lawn maintenance requirements has necessitated landscaping professionals to offer competitively priced services.
In the past many devices have been used and proposed for power assisted lawn edging procedures. For example, U.S. Pat. No. 3,192,693, issued Jul. 6, 1965, teaches connecting a lawn edger attachment to either side of a conventional rotary blade type power lawn mower 10 (FIG. 1). Again, in U.S. Pat. No. 3,421,300, issued Jan. 14, 1969, teaches an edger attachment for either permanent or removable attachment to a conventional rotary blade type power lawn mower 15 (FIG. 1). Other power assisted devices for lawn edging have been disclosed, including the disclosures of U.S. Pat. No. 3,653,447, issued Apr. 4, 1972, in which a vertical edger blade is described; U.S. Pat. No. 3,852,944, issued Dec. 10, 1974, in which means for utilizing the exhaust from a gasoline powered engine to blow debris caused by the edging procedure neatly into the adjacent plant bed is described; U.S. Pat. No. 3,977,475, issued Aug. 31, 1976, in which a power assisted lawn edger is described which can be tilted out or into operative position as required; U.S. Pat. No. 5,156,218, issued Oct. 20, 1992, in which a power assisted angled and serrated edging blade to form a trenched demarcation line around intricate mulch and grassy area landscape lines is described.
Similarly, in the past many power assisted devices have been employed and proposed for digging trenches in lawns for laying pipe lines, electrical cable, and the like. In U.S. Pat. No. 3,719,765, issued May 16, 1967, specially designed cutting blades and a shroud mounted at the front of a wheeled internal combustion engine is disclosed, providing for neatly depositing the trenched soil along side of the trench so that is can be quickly and easily pushed back into the trench for recovering items to be placed in the trench; U.S. Pat. No. 4,825,569, issued May 2, 1989, teaches the use of a power assisted trenching blade combined with means for laying a cable in the trench, and back filling the trench with dirt at substantially the same time; U.S. Pat. No. 4,939,854, issued Jul. 10, 1990, discloses a power assisted trenching machine that can be easily converted between push or pull type models by using same parts at the manufacturing stage.
While the above noted edging and trenching devices provide useful solutions to a variety of landscaping procedures, they do not address the specific improvements embodied in the instant invention. In the present invention a cutting blade of either the edging type or trenching type is connected at one end of a pivotable swing arm which in turn is secured to a stand alone machine incorporating the features of the invention, or to a commercial lawn mower. Power assisted by either hydraulic or belt-drive means, the swing arm is caused to pivot up and down rapidly when the cutting blade encounters soil resistance greater than the combined weight of the swing arm and blade, resulting in a smooth, efficient, and "jolt free" edging or trenching operation that was heretofore not possible.
It is therefore a primary object of the invention to provide a power assisted lawn edger-trencher capable of smooth, "jolt free" soil cutting operations.
Another object is to provide a permanently installed hydraulic drive for the pivotable swing arm-cutting blade combination of the invention.
Still another object is to provide for a rapid quick connect of a hydraulic or belt drive to a commercial or residential power mower, either of the rider or walk behind type, for power assisting the pivotable swing arm-cutting blade combination of the invention.
A further object is to provide a stand-alone edger-trencher wherein a standard belt-drive provides the power assist for the pivotable swing arm-cutting blade combination of the invention.
An additional object of the invention is to provide interchangeable edger and trencher blades on the pivotable swing arm of the invention.
Still another object is to provide for operator selected rotational speed control over the cutting blade of the invention.
Yet another object is to provide for operator control of the depth of the groove within the soil during edging or trenching procedures.
A further object is to provide a cutting blade for trenching operations to further assist the smooth, "jolt-free" operation of the pivotable swing arm-cutting blade combination of the invention.
Still another object of the invention is to provide a conventional stand-alone belt driven unit to be able to attach and detach to a commercial or residential mower of either the rider type or walk behind type.